A methodology for the fabrication of composite (Nb205)l-x(SiO2)~ thin-film rugate filters by using pulsed direct current magnetron sputtering is presented. The two materials are mixed using rapidly alternating dep...A methodology for the fabrication of composite (Nb205)l-x(SiO2)~ thin-film rugate filters by using pulsed direct current magnetron sputtering is presented. The two materials are mixed using rapidly alternating deposition technol- ogy. The optical properties of the composite films varying with the composition of the material are studied in detail, Refractive indices between 1.50 and 2.14 can be realized in our coating system. Two designed rugate filters with a re- flection band at the wavelength of 532 nm are fabricated using an automatic deposition process. The microstructure of the rugate filter is investigated by using scanning electron microscopy. The calculated and the measured transmittance spectra axe in good agreement with each other, The causes of the slight differences between them are also analysed.展开更多
The design and the deposition of a rugate filter for broadband applications are discussed.The bandwidth is extended by increasing the rugate period continuously with depth.The width and the smoothness of the reflectio...The design and the deposition of a rugate filter for broadband applications are discussed.The bandwidth is extended by increasing the rugate period continuously with depth.The width and the smoothness of the reflection band with the distribution of the periods are investigated.The improvement of the steepness of the stopband edges and the suppression of the side lobes in the transmission zone are realized by adding two apodized rugate structures with fixed periods at the external broadband rugate filter interfaces.The rapidly alternating deposition technology is used to fabricate a rugate filter sample.The measured transmission spectrum with a reflection bandwidth of approximately 505 nm is close to that of the designed broadband rugate filter except a transmittance peak in the stopband.Based on the analysis of the cross-sectional scanning electron microscopic image of the sample,it is found that the transmission peak is most likely to be caused by the instability of the deposition rate.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10704079 and 10976030)
文摘A methodology for the fabrication of composite (Nb205)l-x(SiO2)~ thin-film rugate filters by using pulsed direct current magnetron sputtering is presented. The two materials are mixed using rapidly alternating deposition technol- ogy. The optical properties of the composite films varying with the composition of the material are studied in detail, Refractive indices between 1.50 and 2.14 can be realized in our coating system. Two designed rugate filters with a re- flection band at the wavelength of 532 nm are fabricated using an automatic deposition process. The microstructure of the rugate filter is investigated by using scanning electron microscopy. The calculated and the measured transmittance spectra axe in good agreement with each other, The causes of the slight differences between them are also analysed.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10704079)the NSAF Joint Fund,China(Grant No. 10976030)
文摘The design and the deposition of a rugate filter for broadband applications are discussed.The bandwidth is extended by increasing the rugate period continuously with depth.The width and the smoothness of the reflection band with the distribution of the periods are investigated.The improvement of the steepness of the stopband edges and the suppression of the side lobes in the transmission zone are realized by adding two apodized rugate structures with fixed periods at the external broadband rugate filter interfaces.The rapidly alternating deposition technology is used to fabricate a rugate filter sample.The measured transmission spectrum with a reflection bandwidth of approximately 505 nm is close to that of the designed broadband rugate filter except a transmittance peak in the stopband.Based on the analysis of the cross-sectional scanning electron microscopic image of the sample,it is found that the transmission peak is most likely to be caused by the instability of the deposition rate.